Yttrium Complexes of Arsine, Arsenide, and Arsinidene Ligands

Abstract

Deprotonation of the yttrium–arsine complex [Cp′3Y{As(H)2Mes}] (1) (Cp′=η5-C5H4Me, Mes=mesityl) by nBuLi produces the μ-arsenide complex [{Cp′2Y[μ-As(H)Mes]}3] (2). Deprotonation of the As–H bonds in 2 by nBuLi produces [Li(thf)4]2[{Cp′2Y(μ3-AsMes)}3Li], [Li(thf)4]2[3], in which the dianion 3 contains the first example of an arsinidene ligand in rare-earth metal chemistry. The molecular structures of the arsine, arsenide, and arsinidene complexes are described, and the yttrium–arsenic bonding is analyzed by density functional theory.

A Low‐Symmetry Dysprosium Metallocene Single‐Molecule Magnet with a High Anisotropy Barrier

“…The O‐Dy‐O angle is 87.5(5)°, the O‐Dy‐Cp cent angles lie in the range 102.6(5)–104.2(5)° and the Cp cent ‐Dy‐Cp cent angle is 141.5(3)° (Cp cent =centroid of the Cp* ligand). The metallocene bending angle subtended at the dysprosium center in 1 Dy is significant because it is approximately 11° greater than the analogous angles in other {Cp 2 Dy}‐based SMMs . The coordination environment of the iron centers in 1 Dy is essentially the same as those found in other Fp‐containing complexes, with Fe‐C(Cp) distances of 2.10(2)–2.12(2) Å (average 2.11 Å) and Fe‐CO distances of 1.663(13) and 1.681(17) Å.…”

“…We have focused on SMMs containing the dysprosium metallocene unit {Cp′ 2 Dy} (Cp′=substituted cyclopentadienyl), that is, [Cp′ 2 Dy(μ‐X)] n ( n= 2, 3) where the μ‐X ligand contains a soft donor, for example, phosphorus, arsenic, sulfur or selenium . U eff values of up to 331 cm −1 have been determined for these and related metallocene SMMs .…”

Magneto-structural correlations in arsenic- and selenium-ligated dysprosium single-molecule magnets

“… 33 The most closely related compounds to 4-Dy are the samarium arsenide complexes [Cp* 2 Sm(AsPh 2 )(L)] (L = thf or nothing), which were formed by samarium( ii ) reduction of Ph 2 As–AsPh 2 . 34 Complex 5-Dy is only the second rare-earth complex of an arsinidene (RAs 2– ) ligand, with the first example being the yttrium complex anion [(η 5 -Cp′ 2 Y) 3 (μ 3 -AsMes) 3 Li] 2– ( 5-Y ), 35 however 5-Dy is the first lanthanide (4f) complex of such a ligand. Selenolate-bridged lanthanide complexes of the type [Cp 2 Ln(μ-SeR)] n are more numerous, 36 however their magnetic properties have not been described.…”

“…In addition, to probe the effects of exchange interactions on the dynamic magnetic properties, all four compounds were studied under conditions of 5% magnetic dilution at the single-ion level. Dilution of 3-Dy into a lattice of 3-Y ( ref. 35 ) was achieved by adding MesAsH 2 to a 1 : 20 mixture of [Cp′ 3 Dy] and [Cp′ 3 Y], resulting in the formation of [(Cp′ 3 Dy 0.05 Y 0.95 )(AsH 2 Mes)] ( Dy@3-Y ).…”

Open Chain Polyarsenides of the Lanthanides

“…[9] In contrastt ot he well-established solid-state chemistry of rare-earth arsenides, [10,11] structurally characterized molecular rare-earth arsenides are uncommon. To the best of our knowledge, only very few structurally characterizedo rgano-arsenide compounds with LnÀAs bonds, namely Ln-AsR 2 [12][13][14][15][16] and Ln-As(R)-Ln, [16,17] are known.R ecently,p olynuclear DyÀAs compounds were investigated in terms of their single-molecule magnet (SMM)b ehaviour by Layfield et al [16] Also recently,w e disclosed the synthesis of three new d/f polyarsenides.…”